From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793648761; b=AgbBOYz9WnIFRMVfft5cBwX+CoTX90RFvQK0D3ayCjX4w/RcCnJcYFpBqD3CE72X4lbi nPDf3okraYCMtldglCXqFTMecmRifZLv5MUuwW+NFxuqDUSuXDa1/9X3stctXVaS2qlG8 m4/RtPa5LPgZobmP+RqqLE7cE7KBYqHrYoHGvl/QyISqUwIcGvKngEsv4MvwspUuAJxMM sjWmDreh5zXGnCNrkAWTXXHViTFNfa2ET5iNBtWMYUN85bR8puGvE/zF2mXppzr4YimEr CwtcM2u1IY+FTP+xqG9Y5z78o74bZE2IO5kuL3t7yAWqyj/HCRs2tcOBz4l0Y2f4SCQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793648761; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To:Cc: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=zNOWmI555Fw3+30jvBoGh2GbL/GiTj451zBYtJZaM6U=; b=QV1VRlUK7d0tb9G6EP6pr6FJQ2A4kxHaVNudB62DLB0xRQeYlommZJ9+RS4BJpFXepwK AlNJko1OkBzVQW4rYb/bWRIqGPRj/gseACIU6oJxdMIGowgiAG228mT3Nr/nPuZffEZWw GbcIxAU+4h7Ec6QM06Ih20bqf0pxhGIxc2dbRJRwJYMhnLtZxpVTekykY4y15mFeHJMBn vcdKr07kyYaap+/GvSMelnB9bNNgVnDjfYdMpLMg4IEhPKPVrLP117vgT2+MczZpzOSSM vGyt5XoSsz1OVfqDP/bd912nioNSrF3eAtHfAkn8CWCOlSDxjkazKE1nOjLZ6SuzVSQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b="Zxd3h7/0"; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6A1D0606D80F for ; Mon, 2 Nov 2026 19:46:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=Zxd3h7/0 Received: by smtp.kernel.org (Postfix) with ESMTPSA id EEDE51F00A17; Mon, 2 Nov 2026 19:46:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793648761; bh=zNOWmI555Fw3+30jvBoGh2GbL/GiTj451zBYtJZaM6U=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=Zxd3h7/0bykMF9nSb33snDNfuWWTl1QitRTK4AoWyHDKkDIB6ml9XmsDSFsLJO9tE VXP48xrqBuhqwgUP8SV3izoR64S/vC5NclmYge47qPa1HMJbSneeIjI0IT9gkijpCn V5Sqpm9jMysjJuRX/DOAkaG7yvwcwnEzpM/C92W2bRgphENZovmZfHHJfCPxmysQta /6X3Jgq02jJPkPySej2hTO56yOPJ+/tzCNf/tfaqmm8nf4hrxQ0fz6tvnDvUowrnq7 8dKT10/j3POvo/vrmTdm66vp3tTMy1Z5Mq5G0PN+RDyU4U0RnIFgzkx7fG/Rb/FmW3 l3LZz8oeyOiDg== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH v5 01/10] dmaengine: dw: Fix XFER bit set, but channel not idle error Reply-To: sashiko-reviews@lists.linux.dev To: "James Hilliard" Cc: linux-serial@vger.kernel.org In-Reply-To: <20261102-submit-dw-dma-synchronize-v1-v5-1-d3207758fbf9@gmail.com> References: <20261102-submit-dw-dma-synchronize-v1-v5-0-d3207758fbf9@gmail.com> <20261102-submit-dw-dma-synchronize-v1-v5-1-d3207758fbf9@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Mon, 02 Nov 2026 19:46:00 +0000 X-Mailing-List: linux-serial@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list > From: Serge Semin >=20 > If a client driver gets to use the DW DMAC engine device tougher > than usual, with occasional DMA-transfers termination and restart, then > the next error can be randomly spotted in the system log: >=20 > > dma dma0chan0: BUG: XFER bit set, but channel not idle! >=20 > For instance that happens in case of the 8250 UART port driver handling > the looped back high-speed traffic (in my case > 1.5Mbaud) by means of the > DMA-engine interface. >=20 > The error happens due to the two-staged nature of the DW DMAC IRQs > handling procedure and due to the critical section break in the meantime. > In particular in case if the DMA-transfer is terminated and restarted: > [ ... ] > Cc: stable@vger.kernel.org > Signed-off-by: Serge Semin > [james: require a locked XFER event and handle an empty active list] > Reviewed-by: Frank Li > Signed-off-by: James Hilliard Sashiko has reviewed this patch and found no issues. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261102-submit-dw-= dma-synchronize-v1-v5-0-d3207758fbf9@gmail.com?part=3D1